A study was carried out to evaluate the effects of strategic early-season treatments with eprinomectin on first-season grazing calves exposed to strongyle infections on a naturally contaminated pasture. Two groups of first grazing season (FGS) calves were turned out in mid-May on two plots that were similar with respect to size and herbage infectivity. They grazed separately until housing at the end of October. One of these groups was given eprinomectin pour-on at turnout and 8 weeks later, while the other group served as untreated controls. The results showed that the treatments reduced gastrointestinal strongyle infections throughout the season as evidenced by lower faecal egg counts and serum pepsinogen levels compared with the controls. Furthermore, the results of herbage larval counts and postmortem worm counts in tracer animals demonstrated that the treatment had reduced herbage infectivity on the 'treated' plot. Finally, the chemoprophylactically treated calves had a better weight gain over the duration of the study than the untreated controls.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/s0304-4017(00)00220-x | DOI Listing |
Animal
November 2024
Centro Universitario de la Región Este, Universidad de la República, Uruguay.
Cow-calf systems grazing native grasslands must transition toward improved economic performance simultaneously with the conservation and improvement of ecosystem services they provide. We present an innovation model with this objective based on a hierarchical model that links functional relationships between state variables, grazing experiments and its validation, and co-innovation at the farm level. This paper describes the hypotheses, designs, and results of the studies, and the role of grazing ecology and herbivore nutrition to support the process of ecological intensification of livestock systems on native grasslands.
View Article and Find Full Text PDFJDS Commun
January 2025
Department of Animal Sciences, Colorado State University, Fort Collins, CO 80523.
This observational study aimed to characterize the seasonal dynamics of automated BCS throughout the lactation of Holstein cows in a pasture-based system with year-round calvings. Examining the association between nadir BCS (nBCS; defined as the lowest daily BCS after calving) and peak milk yield within each calving period (calendar seasons equally divided in early and late) was a secondary objective of this research. Retrospective data included 2,164 lactations in 539 primiparous (PRI) and 1,625 multiparous (MLT) Holstein cows that calved from July 2021 to June 2023 in a commercial dairy farm located in Southern Chile.
View Article and Find Full Text PDFArch Anim Nutr
January 2025
Posgrado en Producción Animal. Departamento de Zootecnia, Universidad Autónoma Chapingo, Texcoco, México.
The and isomers of conjugated linoleic acid (CLA) are associated with anticancer and lipolytic effects in tissues, respectively, but in lactating cows, the latter isomer reduces the milk fat concentration, a detrimental aspect for the dairy industry, as it reduces the yield of milk derivatives. Therefore, the objective of this study was to evaluate the effect of providing protected palmitic acid (PA) to grazing lactating Holstein cows supplemented with soybean oil as a source of conjugated linoleic acid, on milk production, fat concentration and mitigation of milk fat depression. Nine multiparous Holstein cows were used, distributed in three groups of three cows each, with initial means of days in milk, live weight, milk production, and number of calvings: 124 ± 16 days, 494 ± 53 kg, 20.
View Article and Find Full Text PDFParasite Immunol
January 2025
The University of Queensland, Queensland Alliance for Agriculture & Food Innovation, Centre for Animal Science, St Lucia, Queensland, Australia.
Tritrichomonas foetus is a protozoan parasite that causes bovine trichomonosis (also referred to as trichomoniasis) resulting in substantial economic loss in extensive grazing systems. The parasite colonises the reproductive tracts of both male and female cattle, being asymptomatic in males but causing early reproductive failure in infected females. This systematic review aimed to examine research manuscripts describing the development of T.
View Article and Find Full Text PDFJ Dairy Sci
January 2025
Boehringer-Ingelheim Animal Health, Level 2, 3 Te Kehu Way, Mount Wellington, Auckland, New Zealand.
The aims of this study were to assess the effect of meloxicam at the time of lameness treatment for hoof-horn (HH) lesions in dairy cattle on 1) time to lameness soundness post trimming and block application and 2) reproductive success Five seasonal-calving pasture-based dairy farms located in the Waikato region of New Zealand were enrolled into a randomized clinical interventional trial. Farmers were tasked with identifying lame animals over a period of approximately -4 to 6 weeks relative to the herd start of mating (HSM), with lameness subsequently confirmed with lameness score (LS) by trained technicians (0-3 scale, where ≥2 are considered lame). Animals with a LS ≥2 were examined by a veterinarian who then enrolled animals if they presented lame with HH (white-line or sole) lesions.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!